Resident

lately my 951(86) has been making a kind of thudding noise when I turn it off. It almost sounds like some sort of heavy vibration. I think it may be related to the fan somehow. It doesn't happen all the time, usually only when driving for an extended period of time and\or driving faster. It kicks in immediately after turning off and lasts for about 20 secs or so, then tapers off. It doesn't decrease in frequency, just kkind of quits. I think it may be a fan problem because it never happens when the cooling fan isn't running. It also sounds like its coming from roughly the area of the radiator. Could be wrong about that though. Any suggestions on what may be the problem? Thanks a lot.

Tom
86\951\Black